In order to improve the safety and smoothness of flight, and solve the problems of excessive turning angle and too many search path nodes in the traditional A^* algorithm, this paper proposed a synchronous bi-directional A^* search algorithm based on sector field expansion. Firstly, this paper extended the hazardous area boundaries based on the raster map method. Secondly, it designed the A^* algorithm based on synchronous bi-directional search, which dynamically defined the target nodes for forward and reverse search. Aiming at the problem of limiting search angles, this paper proposed a sector expansion strategy in 5×5 domain, and designed an evaluation function with double weight parameters to reduce the generation of redundant points. Finally, in order to verify the effectiveness of the improved algorithm, this paper selected square and irregular shape hazard areas for simulation. The results show that the improved algorithm searches for a smoother path. Compared with the results of the traditional bi-directional A^* algorithm, the length of its search path reduce by 1.65% and 13.16%, and the number of its search path nodes reduce by 42.6% and 46.81%, respectively, under different shapes of hazard areas, which has a strong search efficiency.

[2021-10-08] Accepted Paper /doc/2021.06.0219/v1

[2022-01-05] Printed Article /doc/2021.06.0219/v2